1. Field of the Invention
This invention relates to circuit breakers and, more particularly, it pertains to an arcing contact hingedly mounted for reducing arcing between separating contacts.
2. Description of the Prior Art
Circuit breakers are used in industrial, commercial, and residential applications to provide protection for electrical apparatus and distribution circuits. Upon overcurrent conditions through a connected electrical circuit, the circuit breaker automatically opens to interrupt electric current flow to the circuit. Some circuit breakers utilize direct tripping operation wherein a circuit current flowing through the breaker also flows through a device, such as a bimetal or an electromagnet, to directly actuate a latch mechanism. In multiple circuit breakers employing direct tripping operation, a separate trip mechanism is often employed for each pole.
Overcurrent conditions through any pole of the circuit breaker cause the associated trip device to function, effecting separation of the contacts of that pole. Since it is generally desirable to have all poles of the circuit breaker trip at the same time, such circuit breakers employ a trip bar or other means connecting the various poles of the circuit breaker to provide simultaneous tripping operation of all poles.
Associated with the foregoing is the problem of arcing between contacts when the contacts separate to open a circuit through the circuit breaker. Arcing deteriorates the contacts. Prior circuit breaker structures having high current ratings had hinge rather than shunt connection, but there was no toeing and heeling action between the separating contacts as in lower rated circuit breakers. The disadvantage of such structure has been that it carried current continuously in the same contact area where the current was also interrupted, thus adding to the deterioration of the contacts.